Last year, Gui Cavalcanti and a team from Boston’s Artisan’s Asylum launched a $1.8 million Kickstarter for a combat league featuring 15-foot tall piloted robot mech suits that launch bowling ball-size paintballs at each other. Certainly a geek dream, the campaign still wasn’t able to raise that level of funding. But it did attract the attention of Autodesk, which partnered with MegaBots to build at least one giant fighting robot. Cavalcanti is using Autodesk’s Fusion 360 to design the project.

Now Cavalcanti and his cofounder Matt Oehrlein, along with a team of designers, fabricators, and more, have been working both at Autodesk Pier 9, that pinnacle of corporate Makerspace, Oakland’s American Steel, where the 10-ton crane means he can actually move the 12,000-pound behemoth, and other locations.

It’s on treads, currently, with the right arm completed (the paint cannonball launcher) and the left in the works. The second arm was crowdsourced via a design competition, with the winner submitting a slightly-smaller 11-shot revolver cannon. Cavalcanti is also building two smaller, walking bots, as practice for that mode of locomotion.

All three will be at Maker Faire Bay Area, with the largest firing its giant, 6-inch, 3-pound, custom-made paintballs up to 120 mph at cars. (Don’t worry, not your car.) “It’s the perfect place to demo what the project is,” says Cavalcanti. It’s also an ambitious deadline; “The challenge is the magnitude of the task. We’re building a 12,000-pound robot in three months.”

“Being here in San Francisco and working with Autodesk has made much more possible than we imagined,” he says. “I can call and pick up a thousand pounds of steel in 15 minutes.”